Cutaneous stimulation of the digits and lips evokes responses with different adaptation patterns in primary somatosensory cortex

View/Open

Issue Date

Author

Publisher

Elsevier

Type

Article

Article Version

Scholarly/refereed, author accepted manuscript

Rights

This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License 4.0 (CC BY-NC-ND 4.0), which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Metadata

Abstract

Neuromagnetic evoked fields were recorded to compare the adaptation of the primary somatosensory cortex (SI) response to tactile stimuli delivered to the glabrous skin at the fingertips of the first three digits (condition 1) and between midline upper and lower lips (condition 2). The stimulation paradigm allowed to characterize the response adaptation in the presence of functional integration of tactile stimuli from adjacent skin areas in each condition. At each stimulation site, cutaneous stimuli (50 ms duration) were delivered in three runs, using trains of 6 pulses with regular stimulus onset asynchrony (SOA). The pulses were separated by SOAs of 500 ms, 250 ms or 125 ms in each run, respectively, while the inter-train interval was fixed (5 s) across runs. The evoked activity in SI (contralateral to the stimulated hand, and bilaterally for lips stimulation) was characterized from the best-fit dipoles of the response component peaking around 70 ms for the hand stimulation, and 8 ms earlier (on average) for the lips stimulation. The SOA-dependent long-term adaptation effects were assessed from the change in the amplitude of the responses to the first stimulus in each train. The short-term adaptation was characterized by the lifetime of an exponentially saturating model function fitted to the set of suppression ratios of the second relative to the first SI response in each train. Our results indicate: 1) the presence of a rate-dependent long-term adaptation effect induced only by the tactile stimulation of the digits; and 2) shorter recovery lifetimes for the digits compared with the lips stimulation.

Items in KU ScholarWorks are protected by copyright, with all rights reserved, unless otherwise indicated.

We want to hear from you! Please
share your stories
about how Open Access to this item benefits YOU.

Except where otherwise noted, this item's license is described as: This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License 4.0 (CC BY-NC-ND 4.0), which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.